Apple scab first appears as small, olive-colored lesions on the undersides of the leaves. As the fungus spreads, the top sides of the leaves develop lesions, as well, that may become black or mottled with defined edges. Severely infected trees may become defoliated by mid-summer, making the tree vulnerable to other diseases. The fruit develop black or brown scabs or soft areas.
cytosis. [ 1 sÄ«tÅâ²sis] 2  a condition in which there is a greater than normal number of cells in a tissue or organ.
Phagocytosis is a process used by cells to engulf and subsequently ingest particles of nutrients or bacteria. This process is a very important part of cell function, allowing cells to grab vital nutrients and allowing the body to protect itself from harmful bacteria.